# lazy

<EpicVideo url="https://www.epicreact.dev/workshops/react-performance/lazy" />

👨‍💼 Our app has a neat Globe component that shows the user where they are on the
globe. Cool right? It's super duper fun.

But one day users started complaining the app is taking too long to load. We're
using several sizeable libraries to have the really cool globe, but users only
need to load it if they click the "show globe" button and loading it ahead of
time makes the app load slower.

So your job as a performance professional is to load the code on-demand so the
user doesn't have to wait to see the checkbox.

For this one, you'll need to open the solution in isolation and open the Chrome
DevTools Network tab to watch the JavaScript chunks load when you click "show
globe." Your objective is to have the network load those same chunks so they're
not in the bundle to begin with.

💰 Here's a quick tip: In the Network tab, there's a dropdown for artificially
throttling your network speed. It defaults to "Online" but you can change it to
"Fast 3G", "Slow 3G", etc.

Also, spend a bit of time playing with
[the coverage feature of the dev tools](https://developer.chrome.com/docs/devtools/coverage).
